The nearly 500 American troops sent to Baghdad to bolster security for the U.S. embassy are equipped with Apache attack helicopters and small unarmed surveillance drones, Pentagon officials said Tuesday.

President Barack Obama on Monday ordered 200 additional troops to the Iraqi capital to ensure the safety of American diplomats and other personnel working in the city, as Baghdad government forces face a challenge from advancing Sunni extremists.

President Barack Obama has deployed 200 more troops to Baghdad to protect the U.S. embassy as Iraq's parliament was set to convene Tuesday to seek a solution to the country's sectarian crisis.

"In light of the security situation in Baghdad, I have ordered up to approximately 200 additional U.S. Armed Forces personnel to Iraq to reinforce security at the U.S. Embassy, its support facilities, and the Baghdad International Airport," Obama said in a letter to Congress released Monday.

An angry President Barack Obama said Monday his Republican foes in Congress have refused to pass an immigration reform bill this year, dealing a shattering blow to his top remaining domestic priority.

Obama said he would begin a new effort to fix as much of the broken system as he could on his own, setting up a toxic new clash with Republicans already accusing him of flagrant abuses of presidential power.

The White House is poised to seek about $2 billion in emergency funds to help stem the flow of tens of thousands of Central American children entering the United States illegally. 

The request will add to an already fiery debate in Washington over U.S. immigration reform and growing concerns about the steady increase of minors illicitly smuggled from Central America and across Mexico into the U.S.

One year into congressional efforts to overhaul U.S. immigration reform, the nation's 11 million undocumented migrants are no closer to legal status, with a swelling humanitarian border crisis only highlighting the system's dysfunction.

Reform efforts are dead in gridlocked Washington, and fingers of blame are pointing every which way.

President Barack Obama, in an interview broadcast Friday, dismissed as a "stunt" a Republican threat to sue him and refused to apologize for using executive orders that infuriate his critics in Congress.

Speaker of the House John Boehner announced Wednesday he would file suit against Obama because "the president has not faithfully executed the laws" of the nation.

U.S. President Barack Obama called on Congress Thursday to approve $500 million to train and equip the "moderate Syrian opposition" battling the forces of strongman President Bashar Assad.

In its overseas contingency operations request to Congress, the White House proposed the funding for "vetted elements of the Syrian armed opposition to help defend the Syrian people, stabilize areas under opposition control, facilitate the provision of essential services, counter terrorist threats, and promote conditions for a negotiated settlement."

The U.S. Supreme Court on Thursday placed limits on the president's power to appoint high-level judges and officials while Congress is in recess, ruling that Barack Obama violated the Constitution.

In a keenly anticipated decision, the high court's nine justices invalidated three so-called "recess appointments" made by Obama in early 2012 when the Senate was holding only pro forma sessions every three days.

Powerful Shiite cleric Moqtada al-Sadr vowed to "shake the ground" under the feet of advancing Sunni militants, risking ratcheting up sectarian tensions Thursday in a crisis dividing Iraq along communal lines.

Sadr, whose movement battled U.S. forces in Iraq, also voiced opposition to American military advisers meeting with Iraqi commanders combating an offensive that has overrun swathes of five provinces, killed more than 1,100 people, displaced hundreds of thousands and threatens to tear the country apart -- ideologically and geographically.

U.S. President Barack Obama warned Wednesday that additional sanctions would be in store if Russia does not move swiftly to reduce tensions in eastern Ukraine.

In a telephone call with Italian Prime Minister Matteo Renzi, Obama also vowed to press Russia to persuade separatist groups to abide by a ceasefire agreement, the White House said.